The present invention relates to high-speed signal connections and, more specifically, to techniques for providing such connections between test equipment and devices under test (DUTs).
As test systems use an increasing number of signals to test electronic devices and chips, the reliability of the connections between the test systems and the devices under test (DUTs) becomes increasingly critical. Open or high impedance contacts can cause an otherwise good chip to appear to be bad, and are statistically more likely to occur as the number of signals increases. Much time and effort has been expended improving the reliability of the spring probes (also known as Pogo™ pins) used to make these contacts, but there appears, at least for now, to be a real-world limit of approximately 200 defects per million opportunities (DMPO), a rate described in statistical terms as a failure rate of 5σ. It is a recognized standard in the industry that an acceptable quality product should meet or exceed a 6σ quality standard, or fewer than 3.4 DPMO.
Since it is not possible to meet this standard with conventional spring probe solutions, techniques for achieving this standard are needed.